1. Field of the Invention
The present invention relates to a method for adjusting the sharpness and brightness of a digital image, and particularly to a method for adjusting the sharpness and brightness of a digital image adjustment capable of reducing the memory space.
2. Description of the Prior Art
In order to improve the quality of viewing, it is required to adjust the sharpness and brightness of a digital image. Conventionally, there are two processes for separately adjusting the brightness and the sharpness. In the process of adjusting the sharpness, the following mathematical formula is used.ƒs(x,y)=ƒ(x,y)+AƒH(x,y)
Where ƒs(x,y) is a function for denoting the image after the sharpness adjustment, ƒH(x,y) is a function relating to the high frequency components of ƒ(x,y), and A is the sharpness control parameter and is a real number. If the control parameter A is positive, then the outputted ƒs(x,y) is the sharpened results. If the control parameter A is negative, then the outputted ƒs(x,y) is the blurred result.
Furthermore, in the process of adjusting the brightness, the following mathematical formula is used.ƒB(x,y)=ƒ(x,y)(1+B)
Where ƒB(x,y) is a function for denoting the image after performing the brightness adjustment. B is the brightness control parameter, and is a real number. If the control parameter B is positive, then the outputted ƒs(x,y) is the brightened result. Otherwise, if the control parameter B is negative, then the outputted ƒs(x,y) is the darkened result.
The prior art method is performed on the digital images by separately implementing the adjustment processes of sharpness and brightness. Therefore, in the design of hardware, it is required to perform one step before the other step is performed so that the complexity of the hardware is increased. In addition, a buffer is needed for temporarily storing the outputted data of the previous step so as to require more memory space.